Mineral oil composition



Patented Sept. 9, 1947 MINERAL OIL COMPOSITION Everett W. Fuller,Woodbury, N. J., Horace E. Redman, Wyandctte, MichL, and Henry G.Berger, Glen Rock, N. J assignors to Socony- Vacuum Oil Company,Incorporated, a corporation of New York No Drawing. Application May- 18,1944,

Serial No. 536,196

13 Claims. (01. 252-3237) This invention has to do with thestabilization of petroleum products against the harmful effects ofoxidation and deterioration with use. More specifically, it has to dowith the improvement or stabilization of mineral oil fractions,particularly viscous mineral oils, by the use of novel reactionproducts, or a novel class of reaction products, which when admixed withamineral oil in minor proportions will prevent or delay undesirablechanges taking place in the oil.

- To those familiar with the art it is well known unstable constituentswhich may act as oxidation catalysts have been removed by refiningoperations and also upon the conditions of use.

A large number of characterizing ingredients have been proposed for useas improving agents for petroleum products. For example, variousmaterials containing sulfur or phosphorus, or combinations of theseelements, have been suggested as stabilizing agents for viscouspetroleum oils. Phosphorusand sulfur-containing reaction products ofnumerous hydrocarbons and P235 are typical examples of such agents.Although some of these reaction products are fairly effective as mineraloil stabilizing agents, many of them are not entirely satisfactory forvarious reasons. Some considerably darken the oils in which they areincorporated, thereby militating against their use. Others suffer alsofrom the disadvantage of limited oil solubility and sludgelikecharacter. Still others are undesirable in the relatively small amountsof sulfur and. phosphorus present therein. All of the foregoingundesirable characteristics seriously reduce the saleability of suchproducts in the oil industry. The present invention is predicated uponthe discovery of a novel class of oil-soluble, acidic, phosphorusandsulfur-containing reaction products, and the ammonium and metal saltsthereof, which are capable of effectin improve- .ment of petroleumfractions, particularly viscous mineral oil fractions; These reactionproducts, and the said salts thereof, prevent the formation of acidicoxidation products and sludge in anoil, as Well as inhibit the corrosionof metal use herein are unlike the oxidation products of engine partssuch as alloy-metal bearings which come in contact with the oil. Thesaid improving agents are particularly desirable in View of thefollowing features: they do not impair the color of the oil fraction inwhich they are incorporated; they contain substantial quantities ofphosphorus and sulfur; they do not contain,

sludge-like constituents, and they are readily soluble in oil fractions.

The improving agents contemplated herein are oil -soluble, acidic,phosphorusand sulfur-containing reaction products obtained by reactionof: phosphorus pentasulfide and an oxidized parafiin wax at an elevatedtemperature between about 50 C. and about 125 C., and particularly atabout C. As indicated hereinabove, the

ammonium and metal salts of the aforesaid reaction products are alsocontemplated.

The oxidized paraffin wax reactants used in preparing the aforesaidimproving agents are obtained by the oxidation of'paraffin wax, orparaffin slackwax which contains a predominant proportion of paraffinwax, in combination with an oil fraction. The paraffin slackwaxescontemplated he'reinshould contain at least about 75 per cent ofparaflin wax, in order to obtain effective and desirable reactionproducts of the type defined above. The paraflin waxes generally containat least about 18 carbon atoms, although a paraffin wax containing onthe average of about 24 carbon'atoms and having a melting point of about126F. is preferred. As used herein, and in the appended claims, theterm"parafiin wax is inclusive of the slackwaxes described above. Tooxidize these-waxes, air or oxygen is introduced into a quantity of waxat an'elevated temperature of the order of from about C.'l'.0 about 180C., and preferably at about C. Temperatures below 120 C. may also beused in the oxidation procedure, but extremely long reaction times arerequired to effect substantial oxidation; for practical purposes, then,temperaturesabove about 120 C. are used. While the composition ofthe'oxidized petroleum waxes so obtained is not fully understood, it isknown that they are complex products containing several such oxygenatedhydrocarbon materials as acids, =hydroxy acids, alcohols, aldehydes, ke

amples provided hereinafter.

The oxidized wax reactants contemplated for many hydrocarbon fractionsclosely related to those of paraffin waxes and parahin slackwaxes and,as such, are superior thereto. This superiority carries over in turn tothe reaction products of this invention- Forexamp'le, equal quantitiesof a paraffin wax, a paraflin slackwax and of -hydrocarbon fractionsidentified in Table 1 below were oxidized by blowing air therethrough at160170 C. for approximately the sameperiod of time. The startingmaterials and oxidation products are described in Table'l by theirneutralization number (N. N.), hydroxylnumber and'saponification number,each of "which is determined by standard procedure known in the art.

4. the filtrate therefrom had an N. N. of 71 and con tained 5.06 percent sulfur and 2.06 per cent phosphorus. This reaction product isidentified hereinafter as product A.

- Exam/{P n II A quantity of a parafiin slackwax containing about 80 percent paraffin wax and obtained from a petroleum distillate having aSaybolt Universal "Viscosity (S. U. V.) of 120 seconds at 130 F.,

was oxidized by blowing air therethrough at 160 ber' (NJNJ oraesaponification number of 36,

Table 1 Reaction No. of Hy- Saponi- Starting Material Time Prod Color N.N. droxyl fica'cion (Hrs) duct No. No.

Paraflin wax (A. S. T. M. melting point 126 F.) 31 .1 Light orange. 4436 174 Paraffin-slackwax =31. 5 Y 2 Dark red..' 8 69 Hydrocarbonioil(saybolt Universal Viscosity 32 3 Black 2 1 (S. U. V.) of 66 seconds at210 F.).. Hydrocarbon oil (Saybolt Universal -V'isc0sity 33 4 do 0. 4 1-2 '(S:'U.V.) of 55 seconds at 210 F.).

It will be apparent from'theforegoing tabulation that'parafiin waxandparaffin slackwax oxidize muchmore readilythando other typicalhydrocarbon fractions, and that the oxidation products of th 'said waxesare more suitablefor the purposes of thepresent invention in view oftheir-colorand oxidation characteristics. In-gem eral,'it-;;is-desirab1eto carry the oxidation-to a point where the hydroxyl and saponificationnumbers are-at leastabout-20 and the neutralization number is Within therange '5 to 60.

As contemplate d herein, the amount of PzSs reacted witlranoxidizedpetroleum wax reactant is in-theneighborhood of from about 5 percent to-aboutper cent-by Weight, with about 10 per cent-byweightbeingpreferred.

The reaction temperature used in the-preparation of the acidic reactionproducts defined above is an important consideration. It has been foundthat elevated temperatures from about 50 C; to about-125 C. are requiredin order to obtain the desired products, a and elevated temperatures ofabout-100 C. are.particularlydesirable. If the temperature is too low,as-below about 50 0., little or no reaction occurs and-if too high, asabove about'125 C., undesirable-reaction-products containing appreciablequantities of oil-insoluble, sludge-like materials are obtained. For

example, the reaction product of an oxidized paraffin wax and P285 at150 C. is predominantly a black, tar-like, oil-insoluble material.

Illustrativeof the reaction products contemplated-by-the presentinvention'are' those shown below in Examples I-through IV,

EEXIXMPLE- I "A'- quantity of a 'parafiln' wax having an A.'S. T.

,..M."inelting point of 126 C. and containing an reaction mixture thusobtained was filtered and cent-by weight of P235 at 100- error 3 hours.The

an iodine number-0f 5 and ahydroxylnumberof 69.

(a) A portion of the oxidized-paraffin slackwax parts'by weight) wasreacted wi thl sss (IOpa'rts weight) atl00 C. for 2 hours. Thereactionproduct obtained thereby contained 4.9 per cent sulfur and 1.97per cent phosphorus-and had an N. N. value of 36. This productis'referred to'hereinas product B.

(b) Barium hydroxide octahydrate (Ba (0H) 2.81320) (10. parts by'weight)was reacted with a quantity ofProduct B (100 parts by weight)" at about0., thereby forming the barium salt of product B. The salt thusobtainedproduct C'c'ontained 4.36per cent barium, 4.58 per cent sulfurarid 1.44 per cent phosphorus and had an N.'N. value of- 11.

' EXAMPLE III 'Aboutone'per cent (by weight) of the Y oxidizedparafiin'wax "formed as described in Example I above and having aneutralization number (N. "N.) 'of 40, was added to a 'parafiin"slack'wax (identifiedin Example II) and the resulting mixture wasthenfurther oxidized 'withair at C. for '49 hours. The reaction productthus formed had a neutralization number (N. N.) of '16, a'saponificationnu'mber of 63 and-a hydroxyl number of 24.

One hundred parts by weight of the oxygenated pa'raffi-n wax so formedwas" treated 'w'ithlO parts by weight of P285 'at'l00" 'C. for 5 hours.The reaction. product (product D) contained 4.3 per c'ent"sulfur and2.06 per cent phosphorus and had 'aneutralization number (N. N.) or-28.

EXAMPLE IV (a) A quantity (100 parts by weight) of a highly oxidizedparafiirr wax having a neutralization number '(N. N.) of 51, asaponifica tio'n --r'iumber of 109 'and' a'hydroxyl numberef '56,'wasreacted With'PzSs (10 parts by weight) at 100C. for. 3 hours. Thereaction product (product E) containe'd 5.1'per centsul'furand' 1.12'per 'cerit'ipliosphorus and had a neutralization-number ("N. N.)'of'88.l

(b), Ammonia gas was bubbledthrough a quantity or product E at roomtemperature (about 20- C.); whereupon thetemperature increased severaldegrees and the product became more viscous-H The ammonium salt thusformed con. tained 2.95 per centnitrogen, and is referred to hereinasproduct F. d While the acidic reaction products of this inventio'n, suchas products A, BjD and-Eshown above'in Examples I through IV, areparticularly desirable for use in petroleum fractions (as are the saltsof such products), related'reaction products prepared in a similar.manner from other related hydrocarbonreact'ants are undesirable for suchuse-1,Th i s is demonstrated by the results shown in 'Table 2 below forproducts 3 and 4. The oxidized materials shown. therein arecomparativein that all were'prepared in the. same manner, as-described inconnection with Table 1 above; The'reaction products shown in Table 2were prepared by reacting a quantity of an oxidized material (1, 2, 3,and 4, respectively, of Table 1) with P285 per cent by weight); at 100C.forv the same period of time, about 2 6 with the loss of the section inthe uninhibited oil. The results are set forth in Table 3 below.

LAUSON ENGINE TEST To further demonstrate the effectiveness of thereaction products-of this invention aspetroleum stabilizing agents ablank oil and blends of the oil and typical reaction products,- productC and product D, were subjected to a Lauson engine test. In this test asingle cylinder Lauson engine was run with an oil temperature of 290 F.and a jacket temperature of 212 F. The oil was S. 11.13.

hours. v 10 motor oil, solvent refined. The acidity as Table 2 Hy-Saponi Q J t No. of Product 7 Reaction Per cent Per cent (Table 1) ColorI vN. N. dggyl tillcgg on Product (dolor N. P S

Light orange; e 44 36 174 A Light brown 71 2.06 5.06 Dark red 8 69 36 B36 1.97 4.9 Black 2 l 0 X 12 0. 38 0.97 do 0.4 l 2 7 0.27 0.86

To demonstrate the effectiveness of the reaction products of thisinvention as mineral, oil improvingagents,v oil blends were preparedcontaining small quantities of representative reaction products and theblends and the blank oils were subjected to the various testshereinafter described. It will readily be seen from inspection of theresults of these tests that our reaction products are extremely.effective in stabilizing mne lcils. 1

CORROSION INHIBITION f' Motor oils, especially thoserefined by certainsolvent extraction methods tend to oxidize when submitted to hightemperatures and to, form products that are corrosive to metal bearings.This corrosive action may bequite severe upon said bearings such asthose having the corrosion susceptibility of Cd-Ag alloys and may causetheir failure within a comparatively short time. The rollowing testisused to determine the corrosive action of motor oil on an automobileconnecting rod bearing. 7

The oil used consisted of Pennsylvania neutral and residuum stocksseparately refined by means of Chlorex and then blended to give an S. A.E. 2 0 motor oil with a specific gravity of 0.872,.a flash-point of 435F. and a Saybolt Universal Viscosity of 318 seconds at 100 F. The oilwas tested by adding a section of a bearing containing a Cd-Ag alloysurface, weighing about 6 measured by the neutralization number (N. N.)

and the viscosity in centistokes at 210F. 0f the oil :blank and oilblend were determined after 36 OXIDATION TEST highly refined oil,suitable for use in trans-- formers, had been prepared by treating acoastal distillate with 40pounds of 98 per cent sulfuric grams, andheating it to 175 C. for 22 hours andzthe'lossin .weight of the bearingsection in therinhibited voilican thus be compared directly? acid and108pounds of 103 per cent oleum per barrel; followed by washing and claypercolation. It'had a specific gravity of 0.871, a fiash point of 310 F.and a Saybolt Universal viscosity of 69 seconds at F. This type of oiltends to form acidic products on oxidation. It was tested by heatingsamples to C, and bubbling oxygen therethrough for '70 hours. The acidsthus formed were determined by treating with alcoholic potash. Resultsof the oil alone and for the oil plus a reaction product of the typecontemplated herein are presented in Table 5 below.

Table 5 Concf N. N. Per cent Value Oil alone .Q 25v 0 Oi1+0.1 Product C0.1 0. 10 Oil-l-OJ Product D 0.1 O. 05

RING. SIICKING AND SLUDGE INHIBITION That the reaction productscontemplated herein are particularly effective in decreasing thetendency of petroleum lubricatin oils to cause ring sticking and sludgedeposition during the operation of an internal combustion engine isdenoted by the results given below in Table 6. This is shown by resultsof the following test which involves the operation of a single cylinderC. F. R. engine at a speed of 1200 R. P. M. over a time interval of 28hours. The temperature of the cooling medium of the engine was held atapproximately 370 F. and the oil temperature was held at 175 F. duringthe test. The oil used was a lubricating oil stock of 120 secondsSaybolt Universal viscosityat 210 F, and the conditions observed'at theend of the test were: (a) the extent to which the piston rings werestuck, (b) the extent to which the slots in the oil rihgswere filledwith carbonaceous deposits in the oil, and (c) the acidity orneutralization number (N. N.) of the oil, The results; obtained from theblank oil and representative blends of, the, oil and typical reactionproducts are Set; forthin 'I-ablefi below.

l 8 group consisting of an acidic reaction product, anainmoniumsaltthereof and a metal salt-thereof; said acidic reaction product beingobtained by reaction at a temperature between about 50 C. and about 125C. of phosphorus pentasulfide and an oxidized paraffin wax characterizedby a neutralization number from about 5 to. about 60 and hydroxyl andsaponification numbers of at least about 20,, said oxidized paraffin waxbeing obtained by oxidizing a. parafl'ln wax having about ntyo r ar n.atoms and an A. 8.. T.

e n point o 126 F;

Table 6 Ring Conditions, Degrees Slots, Percent Stuck l Filled Deposl HV '7 its N. N.

Oil alone 180 0 360 360 360 70 90 14.0 1. 7 Oi1+1% Product 0. 180 0 0 00 0 Trace 0 5. 9 1. 2 Oil alone 360 O 360 360. 180 60 80 40 13. 8 1.6Oil+1% Product D. 0 0 0 0 0 0 0 0 6.4 1.0

The results set forth in Tables '3 through 6 above. demonstrate that thereaction products contemplated, herein prevent the corrosion of hardmetal bearings, and inhibit the development of acids and carbonaceousdeposits in engines during use. They further indicate that the saidreaction products prevent a substantial increase in viscosity of the oilfrom taking place during such use.

Concentrations of the reaction products contemplated herein from 0.1 percent to 5 per cent may be used to efiect a substantial stabilization ofthe oil fractions in which they are incorporated. In general, however,from 0.1, per cent to 2.0 per cent will be sufiicient. Our reactionproducts may be used either in straight petroleum fractions, or infractions containing other additives used. for other, purposes such asdetergents, pour point depressants, V. I. improving agents, etc., inwhich case-they serve to stabilize theresulting blend without detractingfrom the effectiveness of the other additive or additives that. may bepresen It is to be understoodthat while we have hereinabove describedtypical procedures. for making the oil addition agents contemplatedherein and havereferred to certain specific reaction products andspecific mineral oils, the invention is not limited thereto but includesvariations of the procedures, and other typical reaction products andpetroleum fractions coming within the scope of the appended claims.

We claim:

.1. An improved mineral oil composition com prising a major proportionof a viscous mineral oil fraction having in admixture therewith smallamount, sufficient to enhance the stability of said oil fraction, of anoil-soluble, phosphorusand sulfurcontaining material selected fromtheneutralization number from about 5 to about 60 and hydroxyl andsaponification numbers of at least about 20 3. An improved mineral oilcomposition comprising a major proportionof a viscous mineral oilfraction having in admixture therewith a small amount, sufficient toenhance the stability or said. oil fraction, ofv an oil-soluble,phosphorusand sulfurcontaining material selected from the groupconsisting of an acidic. reaction product, an ammonium salt thereof anda metal salt thereof, said acidic reaction product being obtained byreaction at a temperature between about 50 C. and about C. of phosphoruspentasulfide and an oxidized parafiin wax characterized byaneutralization number from about 5 to about 60 and hydroxylandsaponification numbers of at least about 20.

4. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, suflicient to enhance the stability of said oil fraction, of anoil-soluble, acidic, phosphorusand sulfurcontaining reaction productobtained by reaction at a temperature between about 50 C. and about 125C. of phosphorus pentasulfide and an oxidized parafiin wax characterizedby a neutralization number from about 5 to about 60 and hydroxyl andsaponification numbers of at least about 20.

5.. An improved mineral oil composition comprising a. major proportionof a viscou mineral oil fraction having in admixture therewith a small:amount,.sufficient to enhance the stability of;saidoihfraction, of anoil-soluble, acidic, phosphorus-and Sulfurcontaining reaction productobtained by reaction at a temperature between about .9 and. about. 125C. of phosphorus pentasulfide and an oxidized paraffin wax characterizedby a neutralization number from about to about 60 and hydroxyl andsaponification numbers of at least about 20, said phosphoruspentasulfide representing from about 5 per cent to about per cent byweight of the said oxi= dized parafiin wax.

6. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, suflicient to enhance the stability of said oil fraction, of anoil-soluble, acidic, phosphorusand sulfurcontaining reaction productobtained by reaction at about 100 C. of phosphorus pentasulfide and anoxidized paraflin wax characterized by a neutralization number fromabout 5 to about 60 and hydroxyl and saponification numbers of at leastabout 20.

'7. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, sufiicient to enhance the stability of said oil fraction, of anoil-so1ub1e, acidic, phosphorusand sulfurcontaining reaction productobtained by reaction at about 100 C. of phosphorus pentasulfide and anoxidized parafiin wax characterized by a neutralization number fromabout 5 to about 60 and hydroxyl and saponification numbers of at leastabout 20, said phosphoru pentasulfide representing about 10 per cent byweight of the said oxidized paraflin wax, and the latter being obtainedby oxidizing a paraffin wax having about twenty-four carbon atoms and anA. S. T. M. melting point of 126 F.

8. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, sufficient to enhance the stability of said oil fraction, of anoil-soluble, acidic, phosphorusand sulfurcontaining reaction productobtained by reaction at about 100 C. of phosphorus pentasulfide and anoxidized paraffin slackwax characterized by a neutralization number fromabout 5 to about 60 and hydroxyl and saponification numbers of at leastabout 20, said phosphorus pentasulfide representing about 10 per cent byweight of the said oxidized parafiin slackwax, and the latter beingobtained by oxidizing a paraffin slackwax containing not less than about75 per cent of paraffin wax.

9. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, sufiicient to enhance the stability of said oil fraction, of anoil-soluble, acidic, phos phorusand sulfurcontaining reaction productobtained by reaction at about 100 C, of phosphorus pentasulfide and anoxidized parafiin slackwax characterized by a neutralization number fromabout 5 to about 60 and hydroxy and saponification numbers of at leastabout 20, said phosphorus pentasulfide representing about 10 per cent byweight of the said oxidized parafiin slackwax and the said oxidizedparaiiin slackwax being obtained by oxidizing a paraifin slackwaxcontaining about 80 per cent of paraffin wax.

10. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, sufiicient to enhance the stability of said oil fraction, of asalt of an oil-soluble, acidic, phosphorusand sulfurcontaining reactionproduct obtained by reaction' at a temperature between about 50 C. andabout 125 C. of phosphorus pentasulfide and an oxidized paraflin waxcharacterized by a neutralization numher from about 5 to about 60 andhydroxyl and saponification numbers of at least about 20.

11. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, suflicient to enhance the stability of said oil fraction, of anammonium salt of an oil-soluble, acidic, phosphorusand sulfurcontainingreaction product obtained by reaction at about C. of phosphoruspentasulfide and an oxidized paraflin wax characterized by aneutralization number from about 5 to about 60 and hydroxyl andsaponification numbers of at least about 20, said phosphoruspentasulfide representing about 10 per cent by weight of said oxidizedparaffin wax.

12. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a smallamount, sufficient to enhance the stability of said oil fraction, of ametal salt of an oilsoluble, acidic, phosphorusand sulfurcontainingreaction product obtained by reaction at a temperature between about 50C. and about C. of phosphorus pentasulfide and an oxidized paraffin waxcharacterized by a neutralization number from about 5 to about 60 andhydroxyl and saponification numbers of at least about 20.

13. An improved mineral oil composition comprising a major proportion ofa viscous mineral oil fraction, having in admixture therewith a mallamount, sufficient to enhance the stability of said oil fraction, of abarium salt of an oilsoluble, acidic, phosphorusand sulfurcontainingreaction product obtained by reaction at about 100 C. of phosphoruspentasulfide and an oxidized paraffin slackwax characterized by aneutralization number from about 5 to about 60 and hydroxyl andsaponification numbers of at least about 20, said phosphoruspentasulfide representing about 10 per cent by weight of said oxidizedparaflin slackwax and the said oxidized parafin slackwax being obtainedby oxidizing a parafiin slackwax containing about 80 per cent ofparafiin wax.

EVERETT W. FULLER. HORACE E. REDMAN. HENRY G. BERGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,375,061 Williams et a1 May 1,1945 2,331,923 Musselman Oct. 19, 1943 2,316,088 Loane Apr. 6, 19432,281,824 Bray May 5, 1942 2,242,260 Prutton May 20, 1941

